High flow gas diffuser assemblies, systems, and methods

ABSTRACT

Porous diffuser assemblies including multiple diffuser elements. The porous diffuser assemblies include a diffuser body, a diffuser base coupled to the diffuser body and forming a plenum there between, the diffuser base including a plurality of openings formed therein, and a porous diffuser element disposed in each of the plurality of openings wherein surfaces of the porous diffuser elements are exposed to the plenum. Gas purged chambers and methods of purging a chamber are disclosed, as are numerous other aspects.

FIELD

Embodiments of the present disclosure relate to electronic devicemanufacturing, and more specifically to gas diffuser assemblies,systems, and methods for providing gas purge of a chamber.

BACKGROUND

Electronic device manufacturing systems may include one or more processchambers that are adapted to carry out any number of processes, such asdegassing, cleaning or pre-cleaning, deposition such as chemical vapordeposition (CVD), physical vapor deposition (PVD), or atomic layerdeposition (ALD), coating, oxidation, nitration, etching (e.g., plasmaetch), or the like. One or more load lock chambers may also be providedto enable entry and exit of substrates from a factory interface(otherwise referred to as an “Equipment Front End Module (EFEM)”). Eachof these process chambers and one or more load lock chambers may beincluded in a cluster tool, where a plurality of process chambers andone or more load lock chambers may be distributed about a transferchamber, for example. A transfer robot may be housed within the transferchamber and adapted to transport substrates on one or more end effectorsto and from the various process chambers and one or more load lockchambers. A slit valve opening may be provided between the transferchamber and each process chamber and load lock chamber. One or more endeffectors of the transfer robot may pass through the slit valve openingto place or extract a substrate (e.g., a silicon-containing disc) into,or from, a support (e.g., a pedestal or lift pins) provided within theprocess chamber or load lock chamber.

Once the substrate is properly disposed within the process chamber, theslit valve may be closed, and the processing of the substrate maycommence. As part of the processing, particulates may be formed due tomoving components in the system, relative motion between the substrateand the end effector, and other sources. Regardless of their origin, ifsuch particulates come to rest on the processed substrates, substratequality may be impacted. To minimize particulates, some prior systemshave included a plurality of individual gas diffuser assemblies.Although such systems have been effective at providing particulatereduction, such individual gas diffuser assemblies may suffer fromcertain performance problems and may be relatively costly.

Accordingly, improved gas diffuser assemblies, systems, and methods forchamber gas purge are desired.

SUMMARY

In one embodiment, a gas diffuser assembly is provided. The gas diffuserassembly includes a diffuser body, a diffuser base coupled to thediffuser body and forming a plenum there between, the diffuser baseincluding a plurality of openings formed therein, and a porous diffuserelement disposed in each of the plurality of openings, wherein surfacesof the porous diffuser elements are exposed to the plenum.

In another embodiment, a gas purged chamber is provided. The gas purgedchamber includes a chamber adapted to contain a substrate therein, thechamber at least partially formed by one or more side walls, a chamberlid, and a chamber floor, and a gas diffuser assembly coupled to thechamber lid, the gas diffuser assembly including: a diffuser body, adiffuser base coupled to the diffuser body and forming a gas plenumthere between, the diffuser base including a plurality of openingsformed therein, and a porous diffuser element disposed in each of theplurality of openings, wherein surfaces of the porous diffuser elementsare exposed to the plenum.

In another embodiment, a method of purging a chamber is provided. Themethod includes providing a chamber at least partially formed by achamber body including a chamber lid, one or more side walls, and achamber floor, the chamber containing a substrate, providing gasdiffuser assembly coupled to the chamber body, the gas diffuser assemblyincluding: a diffuser body, a diffuser base coupled to the diffuser bodyand forming a plenum there between, the diffuser base including aplurality of openings formed therein, and a porous diffuser elementdisposed in each of the plurality of openings wherein surfaces of theporous diffuser elements are exposed to the plenum, and purging thechamber by inflow of a purge gas through the porous diffuser elementsdisposed in each of the plurality of openings.

Other features and aspects of embodiments of the present disclosure willbecome more fully apparent from the following detailed description, theappended claims, and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates an isometric top view of a gas diffuser assemblyaccording to the prior art.

FIG. 1B illustrates a bottom isometric view of a gas diffuser assemblyaccording to the prior art.

FIG. 2A illustrates an isometric top view of a gas diffuser assemblyaccording to one or more embodiments.

FIG. 2B illustrates a side plan view of a gas diffuser assemblyaccording to one or more embodiments.

FIG. 2C illustrates a bottom plan view of a gas diffuser assemblyaccording to one or more embodiments.

FIG. 2D illustrates a cross-sectioned side view of a gas diffuserassembly taken along section line 2D-2D of FIG. 2C according to one ormore embodiments.

FIG. 2E illustrates a cross-sectioned side view of another gas diffuserassembly according to one or more embodiments.

FIG. 3A illustrates an isometric view of a chamber lid including a gasdiffuser assembly according to one or more embodiments.

FIG. 3B illustrates a cross-sectioned side view of a load lock chamberof a load lock assembly including a gas diffuser assembly according toone or more embodiments.

FIG. 3C illustrates a cross-sectioned side view of a load lock chamberof a load lock assembly including a gas diffuser assembly integratedinto the chamber lid according to one or more embodiments.

FIG. 4 illustrates a partial cross-sectioned side view of a chamber lidof a transfer chamber including a gas diffuser assembly according to oneor more embodiments.

FIG. 5 illustrates a schematic top view of a semiconductor processingtool including gas diffuser assemblies according to one or moreembodiments.

FIG. 6 illustrates a flowchart depicting a method of purging a chamberaccording to embodiments.

DETAILED DESCRIPTION

Electronic device manufacturing systems may include load lock chambersand transfer chambers as discussed above. Load lock chambers mayinclude, at times, a gas purge into the chamber in an attempt toequalize pressure with an adjacent lower pressure volume to which thesubstrate is entering into. As best shown in FIGS. 1A and 1B, a loadlock may include multiple individual diffuser assemblies 100 coupled tothe chamber lid 105, each including a single diffuser element 110coupled thereto according to the prior art. Likewise, purge of atransfer chamber may include purge through a plurality of individualdiffuser assemblies each including a single diffuser element as is shownand described in disclosed in US Pat. Pub. 2015/0090341 to Ng et al.

Although such individual diffuser assemblies (e.g., diffuser assembly100) may function effectively for their intended purpose, such gas purgesystems may suffer from relatively high gas backpressure, may tend to becostly, and/or may take up a large space on the chamber lid. Thus,improved gas purge assemblies are provided that address one or more ofthese concerns.

In one or more embodiments, a gas diffuser assembly is providedincluding a diffuser body, a diffuser base coupled to the diffuser bodyand forming a common gas plenum between the diffuser body and base,wherein the diffuser base includes a plurality of openings formedtherein. A diffuser element is disposed in each of the plurality ofopenings. The diffuser element may be a porous element, such as a porousdisc. As such, each of the porous diffuser elements is exposed to, andreceives gas from, the common gas plenum, i.e., the porous diffuserelements are arranged as an array on the diffuser base.

Advantageously, in one or more embodiments, lower back pressure may beprovided during operation of the gas diffuser assembly, by reducing theoverall number of plenum chambers, as well as by reducing a number ofsmaller gas connections and conduits. Furthermore, relatively lower costand simplicity of installation may be achieved as compared to using aplurality of individual diffuser elements as provided in the prior art.One or more of these advantages may be achieved through the reduction inthe number of sealing components (e.g., O-rings) and thus potentialareas for leakage, reduction in a number of components including a lowernumber of gas inlet conduits, thus simplifying installation, a reductionin a number of fasteners used to attach the gas diffuser assembly to thechamber lid, and/or a reduction in the amount of overall machining beingperformed on the chamber lid. Moreover, the overall size of the priorart collection of individual assemblies may be made relatively smallerand a relatively larger cross-sectional area of the seal is possible,thus possibly improving sealing to the chamber lid. Some of theseadvantages may be accomplished while also achieving equivalent or lowerparticulate counts within the chamber as compared to prior art systemsincluding a collection of individual gas diffuser assemblies. Thus,embodiments of the present disclosure may provide the same or improvedsubstrate yield from the system/tool using the improved gas diffuserassembly.

In summary, according to one or more embodiments described in thepresent disclosure, improved gas diffuser assemblies, gas purgedchambers, and methods of gas purging a chamber are provided. Theimproved gas diffuser assembly is useful for purging either a load lockchamber or a transfer chamber that are adapted to contain one or moresubstrates and which may be subject to a vacuum change. The chambers mayinclude one or more side walls, a chamber lid, and a chamber floor. Thechamber lid, or optionally, one or more of the chamber floor and/or oneor more side walls, may include one or more gas diffuser assembliesaccording to embodiments described herein.

Further details of example embodiments illustrating and describingvarious aspects and features, including apparatus, system, and methodaspects, are described with reference to FIGS. 2A-6 herein.

FIGS. 2A-2D illustrate various views of a first example embodiment of agas diffuser assembly 200. The gas diffuser assembly 200 may be adaptedfor use in electronic device processing systems that may be adapted toprocess substrates (e.g., silicon-containing wafers, both patterned andunpatterned, masked wafers, plates, discs, or the like) by imparting oneor more processes thereto. The processes may include, but not limitedto, heating, cooling, degassing, cleaning or pre-cleaning, depositionsuch as chemical vapor deposition (CVD), physical vapor deposition(PVD), or atomic layer deposition (ALD), coating, oxidation, nitration,etching (e.g., plasma etch), or the like. In particular, the gasdiffuser assembly 200 may be adapted for use on any system componentincluding a chamber where it is desired to gas purge that chamber fromtime to time. For example, the gas diffuser assembly 200 may be adaptedfor use with a load lock chamber or adapted for use with a transferchamber, where in each case the chamber may be purged from time to timewith a purge gas (e.g., N₂ or other inert gas). The gas diffuserassembly 200 may allow for purging while providing a gentle, preferablylaminar flow through the chamber so as not to disturb, circulate, orrecirculate particulates that may be present in the chamber. As suchparticulate contamination of the substrate in the chamber may be reducedor eliminated.

In more detail, the gas diffuser assembly 200 includes a diffuser body202, a diffuser base 204 coupled to the diffuser body 202 and forming aplenum 206 (a gas containing chamber) there between. The plenum 206 mayinclude a frustoconical upper surface. The coupling between the diffuserbase 204 and the diffuser body 202 may be provided by welding, pressfitting, or some form of clamping action, such as clamping between thediffuser body 202 and a chamber lid, wall or floor.

The diffuser base 204 includes a plurality of openings 208 formedtherein. The gas diffuser assembly 200 further includes a porousdiffuser element 210 disposed in each of the plurality of openings 208wherein surfaces 210S (e.g., upper surfaces in the orientation shown) ofthe porous diffuser elements 210 are exposed to the plenum 206 such thatthe plenum 206 comprises a common plenum supplying purge gas to all theporous diffuser elements 210. The plurality of openings 208 may becircular openings configured to receive disc-shaped porous diffuserelements 210 therein. Other shapes are possible, such as rectangular,square, triangular, or the like.

The gas diffuser assembly 200 may include a gas entry 212 (FIG. 2D) intothe plenum 206 through the diffuser body 202. A supply conduit 214 maybe coupled to the gas entry 212. A suitable gas fitting 216 may becoupled to the supply conduit 214. However, and suitable means forintroduction of purge gas into the plenum 206 may be used. A pluralityof holes 218 may be arranged around the periphery of the diffuser body202 to receive fasteners (e.g., bolts or screws) that thread intothreaded bores of the chamber lid, side wall, and/or chamber floor.Other suitable means for fastening the diffuser body 202 to the chamberlid, side wall, and/or floor may be used.

A seal (not shown), such as an elastomeric O-ring seal, may be receivedin a sealing groove 220 formed in the diffuser base 204 or optionallyformed in the diffuser body 202, or even in the chamber lid, side wall,and/or chamber floor (depending on where the gas diffuser assembly 200is located). The elastomeric O-ring seal may have an outer diameter ofbetween about 140 mm and 230 mm and a cross-sectional diameter ofbetween about 2.6 mm and about 5.3 mm, for example. Other O-ring sizesor types of seals may be used, such as a gasket, sealing compound, orthe like.

Each of the porous diffuser elements 210 may be manufactured from aporous metal, a porous ceramic, or a compressed wire mesh, for example.Other suitable materials providing suitable filtering capability may beused. The porosity of the porous diffuser elements 210 may be openporosity. Porous diffuser elements 210 may have a mean pore sufficientto filter the particulates of interest, for example. The porosity of theporous diffuser elements 210 may be formed such that they effectivelyremove/filter out particulates having a mean diameter of greater thanabout 0.003 micron. The particulates may be filtered with greater than99.99% retention, greater than 99.9999% retention, greater than99.999999% retention or even greater than 99.9999999% retention, forexample. In one or more embodiments, the porous diffuser elements 210may effectively remove/filter out particulates having a mean diameter ofgreater than about 0.003 micron with greater than 99.9999999% retention.The porous diffuser elements 210 may be coupled to the plurality ofopenings 208 by any suitable means, such as welding, braising, adhering,mechanical coupling (e.g., clamping), or the like.

In the case of a porous diffuser element 210 made of a porous metal, themetal may be a high purity metal, such as stainless steel or nickel orcomposites thereof. The porous diffuser element 210, when a metal, maybe welded into the plurality of openings 208. The porous metal may beformed by sintering, for example. In the case where the porous diffuserelement 210 is a porous ceramic, the porous ceramic may be an alumina,silica carbide, or even cordierite ceramic. Other types of porousceramics may be used.

The porous diffuser elements 210 may be circular-shaped discs and havean outer diameter of between about 50 mm and about 100 mm, for example.The porous diffuser elements 210 may have a thickness of between about 2mm and about 8 mm, for example. The thickness of the porous diffuserelements 210 may be less than a thickness of the diffuser base 204, suchthat the openings 208 may have transitions formed thereon, such as radiior chamfers to help transition the flow into the chamber whileminimizing turbulence. The outer diameters of each of the porousdiffuser elements 210 may be roughly the same as each other or mayoptionally be of different diameters. Other diameters and thicknesses aswell as other shapes of the porous diffuser elements 210 may be used.

In the case of porous ceramics or wire metal mesh, the porous diffuserelements 210A of the gas diffuser assembly 200A may be secured in theopenings 208 by a securing member 222, such as is shown in FIG. 2E. Asshown, the porous diffuser elements 210A may be clamped between thesecuring member 222 and the diffuser base 204 to hold them in place.Securing member 222 may be a ring or other suitably-shaped structurethat is attached to the diffuser base 204 by fasteners (e.g., screws orthe like).

The wire mesh may be made of a spring material of suitable stainlesssteel wire that is formed with a coil spring shape and then compressedin a die to a suitable density to provide filtering capabilities. Thewire may be piano wire having a diameter between about 0.0035 inch (0.09mm) and about 0.02 inch (0.5 mm). Coil spring pitch may be between 0.05inch (1.3 mm) and about 0.3 inch (7.6 mm), for example. Other details offormation may be found in U.S. Pat. No. 4,514,458, for example.

FIGS. 3A and 3B illustrate a gas diffuser assembly 200 installed on, andsealed to, a chamber lid 305 of a load lock assembly 301. The chamberlid 305 is configured for coupling and sealing to a load lock chamberbody 327 of a load lock assembly 301. The chamber lid 305 may includeapertures 324 formed around a periphery thereof and may be configured tocouple to the chamber body 327, such as to the top ends of the sidewalls thereof by lid fasteners 329. Likewise, the gas diffuser assembly200 may be configured to couple to the chamber lid 305 by diffuserfasteners 326. Lid fasteners 329 and diffuser fasteners 326 may bebolts, screws, or the like. Any suitable seal may be used to seal thechamber lid 305 to the chamber body 327, such as an O-ring, gasket,sealing compound, or the like. Likewise, any suitable seal may be usedto seal the gas diffuser assembly 200 to the chamber lid 305, such as anO-ring, gasket, sealing compound, or the like. The seal may be locatedat any suitable location, such as between the diffuser body 202 and thechamber lid 305, or between the diffuser base 204 and the chamber lid305, for example. In the depicted embodiment, an O-ring seal is receivedin an O-ring groove 320 (e.g., an annular groove) formed in the diffuserbody 202. A similar O-ring groove of a suitable shape may be provided inthe chamber lid 305 of chamber body 327 to allow sealing of the chamberlid to the chamber body 327.

The load lock assembly 301 may include a support assembly 331 that isadapted to support the substrate 325 as the substrate 325 passes throughthe load lock assembly 301 for entry or exit from processing. Substratesmay pass into and out of the load lock assembly 301 through load lockslit valve openings 335 (one of two shown). Support assembly 331 may bea lift assembly including lift pins 331P raised and lowered by liftmember 331M under the force provided by lift actuator 331A. A thermalmember 337 may be provided to heat or cool the substrate 325 as itpasses through the load lock assembly 301. Heating may be provided uponentry or cooling may be provided upon exit of the substrate 325 bycontact with the thermal member 337 via lowering of the lift pins 331Pto bring the substrate 325 into thermal engagement with the thermalmember 337. Any suitable level of heating and/or cooling may beprovided, as desired, for the process taking place in the tool. Heatingand/or cooling may be provided by any suitable mechanism, such asresistive heating, or optionally fluid-containing passages carryingflows of heated or cooled liquid or gas to and from the thermal member337, as shown by arrows. Any suitable vacuum for the process may beprovided by evacuation assembly 338 including a vacuum pump 338P and acontrol valve assembly 338V.

Purge gas used for the gas purge may be provided by a purge gas supply340. Purge gas supply 340 may include a purge gas source 340S, such as apressurized gas-containing vessel, a flow control assembly 340V, whichmay comprise one or more flow control valves and/or one or more massflow controllers, or combinations thereof, adapted to control purge gasinflow, and a purge gas controller 340C operably configured to controlgas flow through the flow control assembly 340V, the vacuum pump 338P,and the control valve assembly 338V. Purge gas controller 340C may beoperatively configured to control the purge gas flow both into and outof the load lock chamber 328. The purge gas supply 340 may include oneor more pressure sensors (not shown), which are used to determine whenthe desired vacuum is achieved. Any suitable vacuum level may be used,such as 1.0×10⁻⁶ Torr or more. Other vacuum levels may be used.

FIG. 3C illustrates a gas diffuser assembly 200A integrated into achamber lid 305 of a load lock assembly 301A. The chamber lid 305A isconfigured for coupling and sealing to a chamber body 327 of the loadlock assembly 301A. The chamber lid 305A may include apertures 324formed around a periphery thereof and may be configured to couple to thechamber body 327, such as to the top ends of the side walls thereof bylid fasteners 329. Lid fasteners 329 may be bolts, screws, or the like.Any suitable seal may be used to seal the chamber lid 305A to thechamber body 327, such as an O-ring, gasket, sealing compound, or thelike. In the depicted embodiment, an O-ring seal is received in anO-ring groove 320A (e.g., an annular groove) formed in the chamber lid305A. In the depicted embodiment, the diffuser base 204 and the porousdiffuser elements 210 may be the same as previously described. Thediffuser body 202, in the depicted embodiment may be made integral withthe chamber lid 305, i.e., made from the same piece of material. Theremainder of the load lock assembly 301A may be the same as describedherein.

It should be recognized that the gas diffuser assembly 200 shown anddescribed herein may be used in other installations. Furthermore, gasdiffuser assembly 200 may be used as a gas purge entry or as a gas purgeexit, or both. For example, one or more of the gas diffuser assemblies200 may be used on, and coupled to, a side wall or a chamber floor, orto any two of the chamber lid 305, side wall, or chamber floor, or toall three of them, depending upon the available entry and/or exitlocations for the gas purge. As shown, the gas diffuser assembly 200 maybe recessed into the chamber lid 305, by providing a recessed region 341in the chamber lid 305. In other embodiments, the diffuser assembly(e.g., diffuser assembly 200A) may be integrated into the lid, floor orwalls.

In another embodiment, as shown in FIG. 4, a transfer chamber purgeassembly 400 is provided. The gas diffuser assembly 200B of the transferchamber purge assembly 400 may be coupled to a chamber lid 405 of atransfer chamber 428, as shown. Optionally, the gas diffuser assembly200B may be coupled to one or more suitable locations on a side wall407, and/or on a chamber floor 411 of the transfer chamber 428. Transferchamber 428 is defined by the chamber floor 411, side walls 407, andchamber lid 405, diffuser base 204 and porous diffuser elements 210.Transfer chamber 428 may be configured to contain a transfer robot 430that may be configured and adapted to transport a substrate 325 toand/or from various process chambers 432 (shown partially and dotted)through process chamber slit valve openings 433 by lowering processchamber slit valve doors 433D. Likewise, transfer robot 430 may beconfigured and adapted to transport a substrate 325 to and/or from oneor more load lock chambers (e.g., 328 of FIG. 3A-3B) through load lockslit valve opening 335 (load lock slit valve door not shown forclarity). For example, the transfer robot 430 may be of any suitableconstruction, such as described in U.S. Pat. Nos. 5,789,878; 5,879,127;6,267,549; 6,379,095; 6,582,175; and 6,722,834; and US Pat. Pubs.2010/0178147; 2013/0039726; 2013/0149076; 2013/0115028; and2010/0178146, for example. Other suitable robots may be used. Transferrobot 430 and process chamber slit valves doors 433D and load lock slitvalve door or doors (not shown) may be controlled by signals to slitvalve actuators 434S and robot drive motor 434R from a mechanicalcontroller 437. Mechanical controller 437 may also interface withsupport assembly 331 (shown in FIG. 3B) and control the lifting andlowering thereof.

As discussed above, the gas diffuser assembly 200B may be used in otherlocations of the transfer chamber purge assembly 400. In an embodimentwhere a gas diffuser assembly 200B may be coupled to, and used on, thechamber floor 411, one or more gas diffuser assemblies 200B that may besmaller than the one shown in FIG. 4 coupled to the chamber lid 405 maybe located at the locations of the gas exit ports 436 of the chamberfloor 411, where purge gas exits the transfer chamber 428 into anexhaust assembly 438. The exhaust assembly 438 may include one or moreconduits 438C1, 438C2, one or more control assembly 438V, a vacuum pump438P, and a vent 439 or optionally a gas treatment apparatus (notshown).

As shown in FIG. 4, gas entry may be through the supply conduit 214 andmay be coupled to a purge gas supply 440. Purge gas supply 440 mayinclude a purge gas source 440S, such as a pressurized gas-containingvessel, a flow control assembly 440V, which may comprise one or moreflow control valves and/or one or more mass flow controllers, orcombinations thereof adapted to control purge gas inflow, and a purgegas controller 440C operably configured to flow through the flow controlassembly 440V, the vacuum pump 438P, and the control assembly 438V.Purge gas controller 440C may be operatively configured to control thepurge gas flow both into and out of the transfer chamber 428. The purgegas supply 440 may include one or more pressure sensors (not shown),which are used to determine when the desired vacuum is achieved.

In some instances where more than one gas diffuser assembly 200B is usedin the system, the purge gas supply 440 may also include an intakemanifold (not shown), which may be a collection of gas flow pathways(e.g., conduits) that are coupled between the flow control assembly 440Vand the gas entry into each gas diffuser assembly 200B. Purge gas maycomprise any suitable gas for the process, such as N₂. Other gases, suchas inert gases (e.g., Helium, Argon, or the like) may be used.

In operation, flow of the purge gas from the purge gas source 440S flowsinto the plenum 206 and is distributed to each of the porous diffuserelements 210, approximately equally. Upon exiting diffusely from theporous diffuser elements 210, the purge gas may flow downwardly and overthe substrate 325 in the transfer chamber 428, blanketing the substrate325 with purge gas flow. As shown, a single gas diffuser assembly 200Bcomprising multiple porous diffuser elements 210 is shown coupled to thechamber lid 405 of the transfer chamber 428. However, more than one gasdiffuser assembly 200B may be used when the transfer chamber 428 isrelatively large (See FIG. 5).

Operation of the purge gas supply 440 may be adjusted via controlsignals to the flow control assembly 440V from purge gas controller 440Cto provide, in some embodiments, a laminar gas flow pattern above thesubstrate 325. Purge gas flow rates of between about 1 slm and 500 slmmay be provided to the gas diffuser assembly 200B. Gas flow adjustmentsmay be made by adjusting the overall flow rate of the purge gas from thepurge gas source 440S to the supply conduit 214.

FIG. 5 illustrates a schematic top view of a semiconductor deviceprocessing assembly 500 including multiple gas purge assemblies 200.Transfer chamber gas diffuser assembly 400A, in this embodiment,includes, as shown, a chamber lid 505 including a plurality of gas purgeassemblies 200 coupled thereto for providing purge gas to the transferchamber (formed underneath chamber lid 505). The gas purge assemblies200 may provide purge gas flow entering into the transfer chamber abovea line of movement 545, shown dotted, of the substrates 325 as thesubstrate 325 enters into and/or exits from the various chambers(process chambers 532A-532F and load lock chambers of load lockassemblies 301. Purge gas flow may be laminar between the substrates 325and the chamber lids 305, 505 in some embodiments.

As shown, load lock assemblies 301 couple between and allow passage ofsubstrates 325 between the transfer chamber underneath chamber lid 305and a factory interface chamber 555 of an equipment front end module(EFEM) 554. A load/unload robot 556 (shown dotted), such as aconventional SCARA robot moveable on a track, may be used to transferthe substrates 325 between substrate carriers 560 docked to load portsof the EFEM 554, and the load lock assemblies 301.

A method 600 of purging a chamber (e.g., load lock chamber 328 ortransfer chamber 428) according to one or more embodiments is providedand described with reference to FIG. 6. The method 600 includes, in 602,providing a chamber (e.g., load lock chamber 328 or transfer chamber428) configured to contain a substrate (e.g., substrate 325), and, in604, providing gas diffuser assembly (e.g., gas diffuser assembly 200,200B) coupled to the chamber, the gas diffuser assembly including: adiffuser body (e.g., diffuser body 202), a diffuser base (e.g., diffuserbase 204) coupled to the diffuser body and forming a plenum (e.g.,plenum 206) there between, the diffuser base including a plurality ofopenings (e.g., openings 208) formed therein, and a porous diffuserelement disposed in each of the plurality of openings wherein surfaces(e.g., surfaces 210S) of the porous diffuser elements (e.g., porousdiffuser elements 210) are exposed to the plenum.

The method 600 further includes, in 606, purging the chamber (e.g., loadlock chamber 328 or transfer chamber 428) by inflow of a purge gas(e.g., N₂ or other suitable gas) through the porous diffuser elements(e.g., porous diffuser elements 210) disposed in each of the pluralityof openings (e.g., openings 208), and into the chamber. The flow may bediffused so that the flow over the substrate 325 contained in thechamber (e.g., load lock chamber 328 or transfer chamber 428) may belaminar.

The foregoing description discloses example embodiments. Modificationsof the above-disclosed assemblies, systems, and methods which fallwithin the scope of the disclosure will be readily apparent to those ofordinary skill in the art. Accordingly, while the disclosure has beenprovided in connection with certain example embodiments, it should beunderstood that other embodiments may fall within the scope, as definedby the appended claims.

What is claimed is:
 1. A gas diffuser assembly, comprising: a diffuserbody; a diffuser base coupled to the diffuser body and forming a plenumthere between, the diffuser base including a plurality of openingsformed therein; and a porous diffuser element disposed in each of theplurality of openings wherein surfaces of the porous diffuser elementsare exposed to the plenum.
 2. The gas diffuser assembly of claim 1,wherein each of the porous diffuser elements comprises a porous metal, aporous ceramic, or a compressed wire mesh.
 3. The gas diffuser assemblyof claim 1, wherein the plurality of openings comprises three or more.4. The gas diffuser assembly of claim 1, wherein each of the porousdiffuser elements comprises a sintered porous metal welded to thediffuser base.
 5. The gas diffuser assembly of claim 1, coupled to achamber lid.
 6. The gas diffuser assembly of claim 1, wherein each ofthe porous diffuser elements are clamped to the diffuser base by asecuring member.
 7. The gas diffuser assembly of claim 1, comprising anO-ring groove formed in the diffuser base.
 8. The gas diffuser assemblyof claim 1, comprising an O-ring groove formed in the diffuser body. 9.The gas diffuser assembly of claim 1, wherein the plenum includes afrustoconical surface.
 10. The gas diffuser assembly of claim 1, whereinthe plurality of openings are circular openings configured to receivethe porous diffuser elements that are configured to have a disc shape.11. The gas diffuser assembly of claim 1, wherein a thickness of theporous diffuser elements is less than a thickness of the diffuser base.12. A gas purged chamber, comprising: a chamber configured to contain asubstrate therein; and a gas diffuser assembly coupled to the chamber,the gas diffuser assembly including: a diffuser body, a diffuser basecoupled to the diffuser body and forming a gas plenum there between, thediffuser base including a plurality of openings formed therein, and aporous diffuser element disposed in each of the plurality of openings.13. The gas purged chamber of claim 12, wherein the gas diffuserassembly is coupled to a load lock chamber lid.
 14. The gas purgedchamber of claim 12, wherein the gas diffuser assembly is coupled to atransfer chamber lid.
 15. The gas purged chamber of claim 12, comprisinga plurality of the gas diffuser assembly coupled to a transfer chamberlid.
 16. The gas purged chamber of claim 12, wherein a thickness of theporous diffuser elements is less than a thickness of the diffuser base.17. The gas purged chamber of claim 12, a wherein the diffuser baseincludes transition elements.
 18. A method of purging a chamber,comprising: providing a chamber configured to containing a substrate;providing a gas diffuser assembly coupled to the chamber, the gasdiffuser assembly including: a diffuser body, a diffuser base coupled tothe diffuser body and forming a plenum there between, the diffuser baseincluding a plurality of openings formed therein, and a porous diffuserelement disposed in each of the plurality of openings wherein surfacesof the porous diffuser elements are exposed to the plenum; and purgingthe chamber by inflow of a purge gas through the porous diffuserelements disposed in each of the plurality of openings and into thechamber.
 19. The method of claim 18 wherein the purging comprisespurging a transfer chamber.
 20. The method of claim 18 wherein thepurging comprises purging a load lock chamber.